1. Technical Field
This invention relates generally to electrical connectors for printed circuit boards, and more specifically to packaging for miniature contact blocks that are to be coupled to high density printed circuit boards.
2. Background Art
Electronic devices are becoming smaller and smaller. It seems not long ago that the use of a portable telephone meant having to carry around a bag the size of a shoebox. By contrast, today's cellular phones are less than 8 cubic inches. They easily fit into a shirt pocket.
The battery packs for these electronic devices have gotten smaller as well. New battery technologies allow battery designers to build batteries less than 2 cubic inches in size that provide hours of talk-time energy to a cellular phone.
To be effective, these new battery technologies require peripheral electronic circuitry. For example, an ordinary lithium based battery needs a safety circuit and an overcurrent device. These components are generally mounted on a very small printed circuit board coupled to the battery.
The problem with the miniaturization of these battery packs lies in the connector. Today's electronic devices often draw large amounts of current. To reliably get the current from the battery to the phone, a robust electrical connector must be used. The connector must be large enough so as to deliver the current to the electronic device without adding too much electrical resistance. Consequently, sometimes the connector is nearly as big as the battery's printed circuit board.
These connectors generally come in one of several well-known packages. These include tape and reel packaging, plastic trays, tubes, bags, embossed tape, radial tape and metal strips. The typical manufacturing process involves either a machine or human picking up a single connector, placing it on the board then soldering the connector to the board.
The problem with this cumbersome manufacturing process is twofold: First, it is slow and costly to place a single part at a time, especially when with human labor. Second, machine placement requires large parts with stable centers of gravity. As the machine places parts into a tacky solder paste, parts that are too small may tip over, thereby causing defective solder connections.
There is thus a need for an improved means of coupling miniature electrical connectors to small printed circuit boards.